Table 3.

Summary of studies on BIS and mortality

Characteristics	Monk et al.; 2005[68]	Lindholm et al.; 2009 [69]	Leslie et al.; 2010 [70]	Kertai et al., 2010 [34]	Kertai et al., 2011[71]
Number of patients studied	1,064	4,087	2,463	460	1,473
Cardiac surgery patients (%)	0	0	49	100	0
Age (yr)	51 (37-65)	50 (36-65)	61 (46-71)	64 (55-73)	59 (48-69)
Male sex (%)	37	38	62	62	51
ASA physical status ≥3 (%)	35	6	74	98	63
Duration of anesthesia (h)	3.1 (2.3-4.3)	1.8 (1.2-2.5)	3.1 (1.4-4.4)	6.1 (5.2-7.1)	3.4 (2.1-4.9)
Volatile maintenance (%)	91	95	57	100	100
BIS monitoring (%)	100	100	50	100	100
Anesthesiologists blind to BIS	Yes	No	No	50%	50%
Average BIS	49±9	37±7	45±7	40±7	45±8
Follow-up (yr)	1	2	4	3	3
30-day mortality (%)	0.7	0.7	4.3	3.5	1.5
1-year mortality (%)	5.5	4.3	10.8	10.7	9.8
2-year mortality (%)	-	6.5	14.6	14.3	16.4
Mortality at the end of the follow-up (%)	-	-	22.2	17.8	22.8
Relative risk for mortality per hour BIS <45 (95%CI)*	1.24 (1.06 to 1.44)	1.08 (0.99 to 1.18)	1.41 (1.02 to 1.95)	1.29 (1.12 to 1.49)	1.03 (0.93 to 1.14)

Table was modified from Leslie et al.,⁷⁰; Data are reported as mean±SD, median (interquartile range), count, or percent; ASA, American Society of Anesthesiologists, BIS, Bispectral Index; CI, confidence interval

^*corrected for clinical risk factors and intraoperative variables